Skip to main content
EricChristenson-at-eaton-com
Associate
April 9, 2024
Solved

STM32H745I I2C Recovery after addressing nonexistent device?

  • April 9, 2024
  • 10 replies
  • 3260 views

I have I2C working properly, but can't seem to figure out how to recover the bus and get it to working again if I test for the presence of a device that is not on the bus and therefore I2C_Mem_Read() returns HAL_ERROR.  There are other devices on the bus, but HAL_ERROR seems to be latched and calling MX_I2C4_Init() again doesn't undo it and allow a retry.  The project is built with EWARM 9.30.1 and STMCubeMX 6.11.0.

Suggestions?  

Background:  I know this is working and checked it against an oscilloscope/protocol analyzer; what's happened is that one of my 2 I2C devices is unplugged and I want to recover from the error.

I2CResult = HAL_I2C_Mem_Write(&hi2c4, (0x22<<1)|0x01, 0x0C, 1, ExpanderConfig, 1, 100);

(device is on I2C4 pins, i2c address is 0x22, register address is 0x0C, address size is 1, we are writing 1 byte of ExpanderConfig, an array, and waiting 100ms for timeout)

I2CResult = HAL_I2C_Mem_Read(&hi2c4, 0x47<<1, 0x08, 1, BufConfig,3,100);

(reading on i2c4 pins, i2c address is 0x47, register address is 0x08, address size is 1, BufConfig is a 3 byte array, and we time out in 100ms.)

 

 

This topic has been closed for replies.

10 replies

waclawek.jan
waclawek.jan
Super User
April 10, 2024

Cube/HAL is written with certain modes of operation in mind (e.g. "everything works, every I2C device is present, device absence is a fatal hardware error which needs fixing and restart") and may not cover your use case.

JW

EricChristenson-at-eaton-comAuthor
Associate
April 10, 2024

(Grin) You may be right, but I am an engineer and it can be said that I study failure....

in this case I might just need the bit to disable I2C4 in hardware to reset the AF (Acknowledge Failure) flag.

 

waclawek.jan
waclawek.jan
Super User
April 10, 2024

> in this case I might just need the bit to disable I2C4 in hardware to reset the AF (Acknowledge Failure) flag.

I'm not sure what is "AF (Acknowledge Failure) flag".

IMO after NACK you should see the NACKF flag to be set; the RM says how to clear it.

waclawekjan_0-1712781564438.png

But if you are talking about some Cube/HAL specific flag, you should resort to Cube/HAL manual; or, if it fails to be informative enough, directly to the Cube/HAL sources - it's open source.

JW

 

mƎALLEm
mƎALLEm
ST Technical Moderator
April 10, 2024

Hello,

Your request has been escalated for further investigation.

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.
Andrew Neil
Andrew NeilBest answer
Super User
April 10, 2024

From the I2C specification:

AndrewNeil_0-1712736669795.png

https://www.nxp.com/docs/en/user-guide/UM10204.pdf

Previously, in the ST Community:

https://community.st.com/t5/stm32-mcus-products/recovering-from-a-failed-i2c-transfer/td-p/97282

https://community.st.com/t5/stm32-mcus-products/how-to-recover-i2c-in-stm32-stm32h743-after-an-error-or-a-locked/td-p/54837

 

#I2CLockup #I2CHangup #I2CRecovery

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    Tesla DeLorean
    Tesla DeLorean
    Guru
    April 10, 2024

    As an Ex-Philips guy, the clocking out of a jam method seems to be a thing people frequently miss.

    Although back in the day you could get buses with devices that were capable of different speeds, and if you had slow devices one also had to consider they might get confused.

    On the ST side, you don't need to drive the R/W bit, the peripheral manages that, and I seem to recall there being a function to probe the address space.

    The transaction really should abort is the slave doesn't NACK to it's address. The slaves shouldn't get confused, but there are a lot of Kinda-I2C implementations

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    Joe WILLIAMS
    Joe WILLIAMS
    ST Employee
    April 10, 2024

    Hi EricChristenson-at-eaton-com

     

    Your post has been reassigned to the online support team for more assistance.

     

    Regards

    Joe

    STMicro Support

    waclawek.jan
    waclawek.jan
    Super User
    April 10, 2024

    I'm not sure we are talking about the jam-requiring-pulsing here. The opening post does not imply that, although we haven't seen nor heard about the waveforms.

    I'd bet this is something around Cube/HAL's ways to handle unexpected situations such as address NAK. We've heard that it does return a generic error, but maybe it then requires some specific handling to resolve the situation (an I2C reset through the enable bit, perhaps?)

    I'm eager to hear what @Joe WILLIAMS finds out about this issue.

    JW

    waclawek.jan
    waclawek.jan
    Super User
    April 17, 2024

    Thanks for coming back with the solution.

    > my target I2C device (TUSB320LAI) needs to have its enable pin in the correct state or it won't talk on I2C at all

    "Nice".

    JW

    Terms & ConditionsAccessibility statement